3,3,3-Trifluoropropionic acid is a significantly important compound as an intermediate for medicines and agricultural chemicals, or as a synthetic intermediate or raw material for producing functional materials such as fluorine-containing polymers. Therefore, processes for producing the same have been reported variously.
In a process disclosed in Non-patent document 1, a carboxylic acid portion of monoethyl malonate ester is substituted with trifluoromethyl group by using sulfur tetrafluoride (SF4). Then, monoethyl malonate ester is hydrolyzed at its ester portion, thereby producing 3,3,3-trifluoropropionic acid. A process disclosed in Non-patent document 2 is to obtain CF3CH2COOSO2OH upon a complex and many-stage reaction, and then hydrolyze it, thereby producing 3,3,3-trifluoropropionic acid. A process disclosed in Non-patent document 3 is to use cyclohexanecarboxylic acid and 1,1-difluoroethylene as starting materials, and to produce 3,3,3-trifluoropropionic acid through four stages.
A process disclosed in Non-patent document 4 is to use ethyl trifluoroacetate as a starting material, and to convert it to 3,3,3-trifluoropropionic acid by using mercury oxide in sulfuric acid. A process disclosed in Non-patent document 5 is to trifluoromethylate 3-bromo-1-propene with trifluoromethylcadmium bromide, and then to oxidize it by using potassium permanganate and crown ether, thereby producing 3,3,3-trifluoropropionic acid. In Non-patent document 6, it is reported that 3,3,3-trifluoropropionic acid is found in a mixture obtained by reacting perfluoro-2-(trifluoromethyl)propene with trifluoromethylthiocopper.
A process disclosed in Non-patent document 7 is to produce 3,3,3-trifluoropropionic acid through a radical addition of trifluoromethyl iodide to t-butyldimethylsilyl enol ether of t-butyl acetate. Patent document 1 discloses an example of producing 3,3,3-trifluoropropionic acid from dimethyl trifluoromethylmalonate by using hydrobromic acid and hydrochloric acid, and an example of producing 3,3,3-trifluoropropionic acid from 1,1,3,3,3-pentafluoro-2-trifluoropropylmethyl ether.
A technique for producing 3,3,3-trifluoropropionic acid by oxidizing 3,3,3-trifluoropropionaldehyde is exemplified by Patent document 2, in which Oxone (registered trade name) (2KHSO5.K2SO4.KHSO4) is employed as an oxidizing agent.
On the other hand, as a technique relating to the present invention, there are various reports concerning 3,3,3-trifluoropropionaldehyde discussed in Patent document 2 to be used as a raw material of 3,3,3-trifluoropropionic acid.
A process disclosed in Non-patent document 8 is to derive 3,3,3-trifluoro-1-propanol from 3,3,3-trifluoropropene by using mercury (II) nitrate and glacial acetic acid and then oxidize it with sodium chromate, thereby producing 3,3,3-trifluoropropionaldehyde. Additionally, a process disclosed in Patent document 3 is to react 3,3,3-trifluoropropene with water in the presence of palladium salts, thereby producing 3,3,3-trifluoropropionaldehyde. A process disclosed in Non-patent document 9 is to add trifluoromethyl iodide to ethyl vinyl ether to be hydrolyzed, thereby producing 3,3,3-trifluoropropionaldehyde. A process disclosed in Patent document 4 is to convert 1-chloro-3,3,3-trifluoropropene into 3,3,3-trifluoropropenyl acetate by using palladium salts, sodium acetate and glacial acetic acid and then hydrolyze 3,3,3-trifluoropropenyl acetate, thereby producing 3,3,3-trifluoropropionaldehyde.
A process disclosed in Patent document 5 is to hydrolyze alkyl 3,3,3-trifluoropropenyl ether by using hydroiodic acid aqueous solution, thereby producing 3,3,3-trifluoropropionaldehyde. A process disclosed in Patent document 6 is to react 1-chloro-3,3,3-trifluoropropene with metal alkoxide in an alcohol (ROH where R has a carbon number ranging from 1 to 4) so as to convert 1-chloro-3,3,3-trifluoropropene into CF3CH═CHOR or CF3CH(OR)2, and then hydrolyze it in the presence of alkanoic acid, thereby producing 3,3,3-trifluoropropionaldehyde. A process disclosed in Patent document 2 is to produce 1-chloro-3,3,3-trifluoropropyl acetate with the addition of trifluoromethanesulfonyl chloride to vinyl acetate and then hydrolyze 1-chloro-3,3,3-trifluoropropyl acetate with sulfuric acid, thereby producing 3,3,3-trifluoropropionaldehyde.
Further, a process disclosed in Non-patent document 10 is to cause a reaction on dimethyl-[1-(2-trifluoromethyl-3,3,3-trifluoropropenyl)]amine (which is a trifluoromethyl group-containing enamine) in the presence of magnesium sulfate hydrate for 28 days, thereby producing 3,3,3-trifluoropropionaldehyde.
None of these commonly known documents discusses a process for improving 3,3,3-trifluoropropionaldehyde in storage stability or a process for collecting 3,3,3-trifluoropropionaldehyde.
Patent document 1: Japanese Patent Unexamined Publication No. 2004-115377
Patent document 2: Japanese Patent Unexamined Publication No. 2003-522743
Patent document 3: Japanese Patent Unexamined Publication No. 63-63633
Patent document 4: U.S. Pat. No. 5,777,184
Patent document 5: U.S. Pat. No. 2,715,144
Patent document 6: U.S. Pat. No. 6,111,139
Non-patent document 1: Journal of Chemical and Engineering Data, Vol. 16, No. 3, p. 376-377, 1971 (United States of America)
Non-patent document 2: Khimiya Geterotsiklicheskikh Soedinenii, No. 10, p. 1321-1324, 1973 (Russia)
Non-patent document 3: Journal of Fluorine Chemistry, Vol. 21, p. 99-106, 1982 (Netherlands)
Non-patent document 4: Acta Chemica Scandinavica, Vol. 43, p. 69-73, 1989 (Sweden)
Non-patent document 5: Journal of Chemical Society, Perkin Transaction 1, p. 2147-2149 (England)
Non-patent document 6: Journal of Fluorine Chemistry, Vol. 63, p. 253-264, 1993 (Netherlands)
Non-patent document 7: Tetrahedron Letters, Vol. 37, No. 11, p. 1829-1832 (England)
Non-patent document 8: Journal of Fluorine Chemistry, Vol. 30, p. 153-158, 1985 (Netherlands)
Non-patent document 9: Zhurnal Organicheskoi Khimii, Vol. 25, No. 7, p. 1376-1380, 1989 (Soviet Union)
Non-patent document 10: Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, p. 1069-1071, 1997 (Russia)